I've always been a fan of the concept behind the AR-7. If it's ever executed properly, it'd be a very useful addition to the outdoors person's kit.
The problem as I see it is that that's never been the case. I've owned at least one example from every outfit that's made them and have had at least some shooting experience with many owned by others.
The basic design is sound, IMO. Where it all falls apart is in the materials and manufacturing. "Built to a price, not a set of specs" pretty much covers it.
Manufacturing tolerances were deliberately 'generous' to speed assembly and materials specs were sacrificed in the interest of absolute economy. Poor QC oversight of vendor-produced parts seems to have been a big factor with all of them.
Of the several I've owned, my original Armalite was the best. It's the only one that didn't have one or more parts fail in-service and the only one that functioned with any acceptable reliability. Even it took some serious tweeking and trying several different magazines before it'd work decently.
Unfortunately, it was stolen along with the rest of my "survival duffle" from the trunk of my car many years ago. All of the others suffered from chronic parts failures, poor functioning including "doubling" and an FA incident and constant feeding issues which couldn't be fixed with new mags or ammo changes.
The last one I'll be buying, a Henry, had the barrel sleeve crack at the extractor cut after fewer than 500 rds. Since Henry won't let me just send them the barrel and shipping the entire rifle both ways at my expense ("Lifetime Warranty" my aching butt!) would cost me nearly two thirds of what it cost originally it lives in its little box at the back of the safe.
If "survival" use in any stretch of the imagination might actually be on your mind - buy the Marlin and a floating case for it.